Die



Jan. 30, 1940. I A lEHlg 2,188,788

DIE

Filed May :1, 1959 INVENTOR ATTORNEY possible fracture,

It is an'object of this 'and held in v I ably-on the spindle prelirninaryto placing the Patented Jan. 30, 1940 'UNI ED?srATEs "PATEN OFFICE I DIE' Alfred J. Kiehne, Derby Line, Vt., assignor to 7 Union Twist Drill Company, Athol, Mass, at corporation of Massachusetts Application May 1, 1939, Serial N0.-271,015 Y i 4 Claims. (01110-119) This invention relates to 5; thread cutting die and mounting therefor for-use in machine tools.

Thread cutting dies a'resep'ar'ate tools adapted to be mounted and dismounted upon a machine 1 tool, to change from a die of one size to a die of another size, or to renew an old die, as may be desired. Such dies are driven about an axis of rotationcommonly a horizontal axis or a vertical axis and they are designed for facility in .niounting and dismounting on a machine tool while providing a good driving connection and a rigid support for the die.

-In the past, such dies have been provided with slots in the'base oi the die, in the form of a kerf,

adapted to fit over a mating projection or rib across the face of the driving spindle. The form'of the slot and mating projection always has been such that the die is mounted in place with the projection engaging in the slot, by moving the die toward the spindle in a direction along the axis of the spindle.

Such a connection is characterized by complete freedom of movement of thedie relative to the spindle in an axial direction. The die is secured in place on the spin dle by a cage or cap which fits over the die and screws onto the end of' the spindle. The cage which the operator with one hand only has to reach downin and replace dies that he cannot fully see, if at all.

" Experience has shown thatin a considerable percent or die. mounting operations an operator fails properly to .align the die with the spindle,

with the "result that, when the cage is tightened on the'clie", frequently the dieis cocked out of alignment with the result that the prongs become excessively flexed or adjused below the intended cutting size. The prongs are thus subjected to and, if the misaligned die is used, it will ruin the work, and injure the die,

holder, or both. Alsoythe care required in properly aligning the die, during mounting, wastes the time of the operator.

invention to provide a novel connection between' a die and'the spindle of a machine by which the die may be arranged place-though movably and adjustcage,thediameanwhile, being supported by the engagement with the'spin dle without the aid of l the cage. It is an object to provide a die having a novel and sufiiiciently loose connection witha spindle with or without frictional holding means and which enables an operator initially to place the die on the spindle in approximate alignment 5.

and in complete driving connection as a prelim inary operation separate from and independent of the subsequent act ofplacing and screwing the cage onto the spindle, which cage then moves the die to and secures it in perfect axial 1 alignment'with the spindle and in proper drivable relation thereto.

Other objects and advantages of the invention appear in the following detailed description taken in connection with the accompanying drawing in which: c

Figure l is a perspective view of a die provicled with spindle connection elements suitable for use in this invention; and

Figure 2 is a view inside elevation, partly in section, showing the complete die and mounting of this invention and illustrates the connection between a spindle and die,,with the retaining and centering cage and locknut in place.

This invention is concerned with the structure and mode of operation of theconn'ection between the dieand the spindle. To avoid axial misalignment or the die, relative'tothe projection on the spindle for engaging and driving the die,

the connection is, so made that the die may be 30 assembled initially and temporarily held on the spindle without the cage (and hence without interference thereby), the machine. operator being able to manipulate the die freely. andpositively when mounting it. To retain the advantage tii gained by providing for free and positive manipulation of the die when mounting it, the assembling connection is somade as to be self sustaining, thereby leaving the operator free to place and screw on the cage Without iurther attentionl to the arrangement of the die on the spindle with but one hand and regardless of whether hecan see what he is doing.

As shown in Fig. 1, the preferred-form of die I is provided with slots 2 in the margin 3 of the (116.11%

,The slots 2 are open along the rim 4 so that a rib projecting from the face of a spindle may engage therein. Slots 2 open into slots 5, there being shouldersii, which extend in a plane substantially perpendicular to the axis of the die. The 1 slots 5 are bounded by, faces I and a, which define the substantially rectangular form of the slots.

The spindle Sis provided with projections l6 which are upstanding from the flat end face it 55 of the spindle in'the direction of the spindle axis" though a single projection would serve as an equivalent, said end face being ground in a plane at right angles to said axis. Thep'rojeiztions it are of a shape and size to fit'freelyand '60 with substantial clearance (as shown) within the slots 2 and 5, the fit being not a close sliding one but free enough so as to permit later the required centering of the die accurately "on and in axial alignment with the spindle whether the required freedom be in line with the slots 2 and 5, laterally of said slots, or any of them, or both. The connection thus permits the die slightly to rock and of inter-engaging slotsand projections shown in Figs. 1 and 2 is but one example which typifies to rotate with reference to the spindle. The die of Fig. 1 is shown, mounted on the spindle '9, in Fig. 2. As shown there, each head II of each projection l0 fits withinthe slots 5 and engages with shoulders 6 and faces 'I and 8. Each stem I2 of each projection I 0 may or may not engage with the walls of slots 2, there being some advantage in providing for such engagement in that greater surface area is provided for transmitting the driving force.

,The slots 2 and 5 are open at the inner and outer surfaces I3 and Id of the end wall I5, which forms the hub or base of the die, said end wall or surface I5 being accurately ground-and in a plane at right angles to the axis of the die I. Also, said end wall, as shown, may have a shallow depression I9 therein, as hereinafter referred to. The die may be mounted upon, or dismounted from, the projections Ill bysliding the die across the face of the spindle 9, the faces of the slots 2 ,and 5 tracking along but freely clearing the surfaces of the projections I I0 and with the surface I5 abutting the ground surface I6 of the spindle.

In practice, an operator takes a die, separately, and slides it in place across the face of the spindle, arranging the projections In in the slots 2 and 5. When the die has been substantially or roughly centered on the spindle the operator releases the die and it hangs in place by virtue of the engagement between the heads I I of projections II] with the shoulders 6 and walls I and 8, of slots 5. The projections II! should extendin a substantially horizontal direction when mounting the die, so that the die may not slide off the projections ID by operation of the force of gravity. This position of the projections It] easily may be arranged by the operator simply by turning the spindle by hand. I

The operator next takes a cage I! and slips it over the die by end-wise movement along the axis of the spindle. The threads of. the cage I"! are engaged with the threads of the spindle 9 and the cage I1 is screwed onto the spindle. As the cage is tightened against the die I, the internal conical or sloping surface of the cage II engages with the sloping surface I8 of the die prongs. This engagement between the, sloping surfaces of the cage and the die operatesto center and axially align the die accurately on the spindle, to clamp the die tightly in place,and to flex the prongs of the die slightly to proper cutting position. The

locknut is then set up to lock the cage in position.

It will be apparent that by separating the operation of". placing the die on the spindle from the operation of screwing the cage on the spindle,

danger of misalignment of the die relative to the driving projections of the spindle is wholly eliminated. While the operation ofmounting the die has been separated into twoparts, each of those parts is so positively under the control of the operator thathe may perform the operation of mounting the die with much more facility than is usual, when the die and the cage are mounted simultaneously, as iscommon practice, andy'rith complete elimination of any-possible misallgn ment or breakage of dies or other parts.

The shape and arrangement .of the slots, in

the die, and the projections, on the spindle, which sufiiciently restrain the die from free movement relative to the spindle in a direction along the axis of the spindle and die, characterize the invention. The particular shape and arrangement the invention, though any one of various shapes .of the slots are suitable for practicing this in vention when used in connection with acomplementary headed or enlarged end projection on.

the spindle, which is of 'suchshape as to fit the slots with the required free sliding fit.

,While it is desirable to make both slots identical with one another'it will be apparent that iden zontal plane so that the die, whenjarranged in place on the spindle, will not slip off the pro- As pointed out here'inbefore in connection with Fig; 2, the orientation ofthe spindle must be'such that the projections I 0 lie'in a substantially horijections. Avoidance of the necessity forarranging the spindle in any particular plane of orientation, incident to mounting the die on the spindle,

is the result which may be achieved,"for example, v

by the use of a suitable friction devicasay byfa depression 19 in the dieand a recess 23,"drilled into the spindle. A ball 24 is located within the recess at the forward end thereof. ,The metal around the open end of the recess 23 is turned in to form a shoulder 25 adequate for retaining= the ball 26 in place. A spring 26 is arranged in the recess 23 and presses the-ball E ise thatthe ball tends to project slightly beyond the fa'ceof the spindle and into the shallow depression I9,

if provided. I v

When the die I is mounted upon the spindle 9 'with'the'proj'ections I0 engaging withinthe slots 5, the ball 24 presses against the surface I d'of the die or into the depression Ififas the case'may I be) ,jadjoining the face of the spindle. The pressure exerted by the spring through the ballon the rear face of the die, holds the die in place'on projections II irrespective of the plane of orientation of" the spindle.

The invention has been described in detail byway of, illustration. It is not intended so to'limit the invention. Variations in thefdetailsof construction may be made, as will be apparentto one skilled in the art, withoutdepartingfrom the scope ofthe invention as defined in the following claims.

This application is a continuation-in-part of my application Serial No. 178,727, filed-December 3, 1937, "said application having been formally abandoned .May 10, 1939.

Having described my invention, what I claim is: c

1. The combination in a die cuttingdevice of a supporting spindle member, a die cutting memher, and a cage, the supporting spindle member having a circular end surface at right angles'to axis of the bore and separated prongs extending F5 outwardly axially, each prong having thread cutting teeth on its inner surface, and a tapered external surface, loosely-fitting headed connections between the abutting ends of the supporting member and the die cutting member, the parts of which connections are mutually engageable by relative radial movement only, said connections preventing direct axial separation of said members and being so loose as to permit one of said members to rock and rotate slightly with relation to the other but being independently capable when said connections are arranged substantially off the vertical of temporarily holding said die cutting member in approximate position on said supporting spindle member prior to and during the assembly of said cage and until the initial screw threaded engagement of said supporting member and cage is accomplished and thereafter to permit. accurate axial alignment and locking of said members in abutting contact by said cage, said cage having at one end an internal, thread adapted to screw onto the external thread of the supporting member and at the other end an internal conical surface adapted to fit the external tapered surfaces of the prongs, whereby when the cage is screwed'down on the supporting member the annular ground ends of that member and of the die cutting members are pressed and the axes of the bores of said members, are brought into alignment and all relative rocking and axial misalignment of said members is prevented.

2. The combination in a die cutting device of asupporting spindle member, a die cutting member, and a cage, the supporting spindle member having a fiat end surface at right angles to the spindle axis and an external thread, the die cutting member having an axial bore, an annular hub having an end surface ground at right angles to the axis of the bore and separated prongs extending outwardly axially, each prong having thread cutting teeth on its inner surface, and a tapered external surface, loosely-fitting headed connections between the abutting ends of the supporting member and the die cutting member, the parts of which connections are mutually engageable by relative radial movement only, said connections preventing direct axial separation of said members and being so loose as to permit one of said members to rock and rotate slightly with relation to the other, and interengaging means to'assist in temporarily holding said die cutting member in approximate position on said supporting spindle member prior to and during the assembly of said cage and until the initial screw threaded engagement of said supporting member and cage is accomplished and thereafter to permit accurate axial alignment and locking of said members in abutting contact by said cage, said cage having at one end an internalthread adapted to screw onto the external thread of the supporting member and at the other end an internal conical surface adapted to fit the external tapered surfaces of the prongs, whereby when the cage is screwed down on the supporting member the flat abutting end of that member andof the die cutting member are pressed together and the axes of the bores of said members are brought into alignment and all relative rocking and axial misalignment of said members is prevented.

3. The combination in a die cutting device of a supporting spindle'member, a die cutting member, and a cage, the supporting spindle member having a flat end surface at right angles to the tapered external surface, loosely-fitting headed connections between the abutting ends ofthe supporting member and the die cutting member, the parts of which connections are mutually en-' gageable by relative radial movement only, said connections preventing direct axial separation of said members and being so loose as to permit one of said members to rock and rotate slightly with relation to the other, and frictional means to assist in temporarily holding said die cutting member in approximate position on said supporting spindle member prior to and during the assembly of said cage and until the initial screw threaded engagement of said supporting member and cage is accomplished and thereafter to permit accurate axial alignment and locking of said members in abutting contact by said cage, said cage having at one end an internal thread adapted to screw onto the external thread of the supporting member and at the other end an internal conical surface adapted to fit the external tapered surfaces of the prongs, whereby when the cage is screwed down on the supporting member the flat abutting end of that member andof the die cutting member are pressed tightly together and the axes of the bores of said members are brought into alignment and all relative rocking and. axial misalignment of said members is prevented.

4. The combination in a die cutting device of a supporting spindle member, a die cutting member, and a cage, the supporting spindle member having a fiat end surface at right angles to the spindle axis and an external thread, the die cuttingmemberhaving an axial bore, an annular hub havingan end surface ground at right angles to the axis of the bore and separated prongs extending outwardly axially, each prong having thread cutting teeth on its inner surface, and a tapered external surface, loosely-fitting headed connections between the abutting ends of the supporting member and the die cutting member, the parts of which connections are mutually engageable by relative radial movement only, said connections preventing direct axial separation of said members and being so loose as to permit one of said members to rock and rotate slightly with relation to the other, and spring-pressed 'means to assist in temporarily holding said die cutting member in approximate position on said supporting spindle member prior to and during the assembly of said cageand until the initial screw threaded engagement of said supporting member and cage is accomplished and thereafter to permit accurate axial alignment of said members in abutting contact by said cage, and the cage having at one end an internal thread adapted to screw onto the external thread of the supporting member and at the other end an internal conical surface adapted tofit the external tapered surfaces of the prongs, whereby when the cage is screwed down on the supportingmember the flat abutting end of that member and of the die cutting member are pressed tightly together and the axes of the bores of said members are brought into alignment and all relative rocking and axial misalignment of said members is prevented.

- ALFRED J. KIEHINE. 

